Apparatus for regulating pressure in tanks



Nov. 15, 1932- c. J. SOYSTER ETAL 1,887,824

APPARATUS FOR REGULATING'PRESSURE IN TANKS Filed Jan. 10. 1930 INVENTORS CHE/P165 J: 50 ysrf/P.

aae o/v 14 LEW/V.

ATTORNEY Patented Nov. 15, 1932 UNITED STATES PATENT OFFICE CHARLES J. SOYSTER AND GORDON W. LAWN, OF LONG BEACH, CALIFORNIA; SAID LAWN ASSIGNOR TO SAID SOYSTEB APPARATUS FOR REGULATING PRESSURE IN TANKS Application filed January 10, 1930. Serial No. 419,827.

This invention relates to improvements in apparatus for controlling the gas pressure on storage tanks.

The principal object of the invention is to provide automatic mechanism for relieving alternations of vacuum pressure on storage tanks containing liquids, volatile at ordinary temperatures, whereby a predetermined pres sure may be maintained on the storage tank without loss of valuable volatile liquids.

The invention finds a particular use in oil refineries and oil tank farms where volatile liquids, such as crude petroleum, gasoline, casinghead gasoline, and the like are stored in large quantities.

It will readily be appreciated in such mixtures of hydrocarbons as gasoline, which may contain propane boiling at about -4 0., butane boiling at about 3 0., pentane boiling at about 36 0., and other heavier associated hydrocarbons, that in ordinary vented storage tanks exposed to the sun and reaching a temperature at times of 40 0., or higher, the vaporization of such hydrocar- 25 bons together with the partial pressure effects will cause a large loss in valuable liquids.

It is therefore desirable to maintain equal pressures inside and outside such storage tanks, which pressure should be atmospheric pressure at all times, without loss of volatile liquids.

With closed storage tanks, a lowering of temperature at night to 10 0. or less after a hot day will cause a vacuum to be created in the vapor space of the storage tank, after vapors have been vented therefrom to relieve abnormal pressures.

It is therefore an object of this invention to provide simplified automatic mechanism for alternatively recovering valuable hydrocarbon vapors and for returning hydrocarbon gases to tanks or other containers, and maintaining equalized pressures within and without a storage tank. Referring to the drawing, which shows an elevation of a suitable apparatus, partly in section, a storage tank 1 is filled to a predetermined height X-X, with voltatile liquids of the class de scribed.

5o The vapor space above the line XX is connected by a pipe 7 to a control mechanism passing through the side wall of a box 27, and terminating under a hell 2, supported in apan 3 by floating in oil or other suitable liquid the end of pipe 7 being always above the variable liquid level 4 in pan 3.

Pan 3 is supported by and fastened to standards 26, and bell 2 is connected to a yoke 5 at the lower end of an adj ustin spring 6, fastened and supported by an a justing nut 25 to the upper end of box 27, the bottom of yoke 5 being joined through the core of a primary coil 8, adjusting spring 24, and ad usting nut 25, to the lower end of box 27.

Coils 9 and 17 are in circuit with coils 9a 17 a respectively, a current being induced therein by the passage of current from a suitable source through a lead wire 8' connected to coil 8, box 27 being grounded and the upper end of coil 8 being attached through proper insulation to yoke 5.

The operation is as follows:

As illustrated in the drawing, there is neither sub-atmospheric nor super-atmospheric pressure in tank 1, and in consequence yoke 5 will be in a certain position predetermined and fixed by adjusting nut 25, this position being such that current passing through the primary coil 8 has little or no effect on secondary coils 9a and 17a, hence coils 9 and 17 are not sufliciently energized to ralse armatures 10 and 18. Thus there will be no movement of Valve arms 12 and 20, connected to armatures 10 and 18 by rods 11 and 19 respectively and valves 13 and 21 will remain closed. I.

The slightest increase in pressure in tan 1 will transmit pressure through pipe 7, raising bell 2, such a rising decreasing the effect of coil 8 upon coil 17a and increasing its effeet on coil 9a to the end that coil 9 is more strongly energized and valve 13 commences to open, valve 21 remaining closed.

Valve 13 will continue to remain open, permitting the passage of vapors from pipe 16 by way of the surge pipe 14 and T fitting 15, until such time as the vapor pressure in tank 1 recedes to a predetermined figure, at which time valve 13 will close due to the reduction of pressure transmitted to bell 2 with consequent lowering of coil 8.

A reverse action to that described will occur when the pressure in tank: 1' decreases, how- 5 ever slightly. The. lower pressure will be transmitted through pi e 7 causing bell 2 to descend and with it coi 8, energizing coil 17 and causing armature 18 and its associated connections to rise and open valve 21 for the admission of a dry gasfrom a supplypiple 22 and a pipe 23 connectingvalve 21 wit t e T fitting 15, which brings the pressure in tank 1 up to the desired figure, valve 13 remaining closed, and upon reaching such figure, valve 21 will be closed.

In this manner an automatic ad'ustment of pressures within tank 1 will 0 effected through a governing device includin parts 2, 3, 4, 5 and 6, WlllCh governing evice by means of the primary coil 8 will cause a solenoid action in coils 9 and 17 to alternatively operate valves 13 and 21. v

No loss in vapors occurs and a minimum desired pressure is maintained in tank 1.

We claim as our, invention:

1. Pressure controlling apparatus comprising, a device movable by fluid pressure, an outlet valve, an inlet valve, means to regulate the position of said device, and electric means responsive to the movement of said regulation means to control the position of said valves; said last mentioned means including an energized coil moving with said device in two induction circuits, and means in each circuit connected to each valve to open one valve while holding the other closed and vice versa.

2. Pressure controlling apparatus comprising, a device movable by fluid pressure, an outlet valve, an inlet valve, means to regu- 40 late the position of said device, and electric means responsive to the movement of said regulation means to control the position of said valves; said last mentioned means including an ener ized coil moving with said device in two induction circuits,and adjustable means in each circuit connected to each valve to open one valve while holding the other closed and vice versa.

3. Pressure controlling apparatus comprising: a float responsive to fluid pressure, an outlet valve, an inlet valve, an energized coil moving with the float alternately in two induction circuits, and a solenoid in each circuit connected one to each valve.

4. Pressure controlling apparatus comprising: a balanced float responsive-to fluid pressure, an outlet valve, an inlet valve, an energized coil moving with the float alternately in two induction circuits, and a solenoid in each circuit connected one to each valve.

In testimony whereof weaflix our signatures.

CHARLES J. SOYSTER. GORDON LAWN. 

